On 4/27/2016 5:34 PM, Arnd Bergmann wrote:> This won't help on TILE, which is the one architecture that sets> ARCH_SUPPORTS_OPTIMIZED_INLINING but does not set ARCH_USE_BUILTIN_BSWAP.> Chris Metcalf should be able to figure out whether we can just> set ARCH_USE_BUILTIN_BSWAP for tile as well.

We certainly could enable ARCH_USE_BUILTIN_BSWAP. The only problem isthat we never added explicit support for bswap16() in gcc, which isefficiently done on tilegx via the "revbytes" instruction and a 48-bitright-shift. So gcc instead does a generic thing with fourinstructions in three bundles, so really not as good as our asm/swab.h.